mercurial: have "qcat" use "colordiff" for syntax higlighting

hosts/common/programs/assorted.nix

@@ -143,6 +143,7 @@ in
       "cdecl"  # like <https://cdecl.org>. `cdecl explain 'struct foo *const inst'`
       # "cdrtools"
       # "clinfo"
+      "colordiff"
       # "dmidecode"
       "dtrx"  # `unar` alternative, "Do The Right eXtraction"
       # "efivar"
@@ -487,6 +488,8 @@ in
       "/var/lib/clightning/bitcoin/lightning-rpc"
     ];
 
+    colordiff.sandbox.autodetectCliPaths = "existingFile";  # for `aplay ./file.wav`
+
     # cryptsetup: typical use is `cryptsetup open /dev/loopxyz mappedName`, and creates `/dev/mapper/mappedName`
     cryptsetup.sandbox.extraPaths = [
       "/dev/mapper"

hosts/common/programs/mercurial/default.nix

@@ -4,6 +4,7 @@
     packageUnwrapped = pkgs.mercurialFull;
     sandbox.wrapperType = "inplace";  # etc/mercurial/hgrc refers to hg python-path (to define an extension)
     suggestedPrograms = [
+      "colordiff"  #< optional, for my hgrc aliases
       "less"  #< TODO: this might be a missing dependency on the nix side of things?
     ];
     sandbox.net = "clearnet";

hosts/common/programs/mercurial/hgrc

@@ -21,7 +21,7 @@ q = qseries -s -v
 qpath = !$HG noop ; echo ".hg/patches-$($HG qqueue --active)" | sed 's:hg/patches-patches:hg/patches:'
 #
 # `hg qcat PATCH_NAME`: view the diff of a mq patch in the current queue.
-qcat = !$HG noop ; cat $($HG qpath)/$1
+qcat = !$HG noop ; cat $($HG qpath)/$1 | colordiff --nobanner
 #
 # `hg qdup NEW_QUEUE_NAME`: copy all patches in the current queue into a new queue
 qdup = !$HG qpop -a ; cp -R $($HG qpath) .hg/patches-$1 ; echo $1 >> .hg/patches.queues ; $HG qqueue $1